Flow switch assembly

ABSTRACT

In a preferred form, this disclosure relates to a flow switch assembly comprising a housing means having a pair of hollow metal housing members which are insulated from each other and which define a flow passage therethrough. The assembly also includes a vane member which is pivotally supported for movement between first and second positions and a spring member which biases the vane member to its first position and normally has its opposite ends engaged with the metal members to provide a conductive path therebetween. The housing means has a recess which extends radially from the flow passage at a location between the first and second positions of the vane member. The vane member is moved from its first toward its second position in response to a fluid flow in excess of a first predetermined magnitude flowing therethrough to break the conductive path and, when the flow decreases to below a second predetermined magnitude less than the first, the vane member moves toward its first position. The recess provides an instantaneous increase in the flow passage area available for fluid flow when the vane member moves toward its first position and is aligned therewith to enable the spring member to rapidly shift the vane member to is first position.

United StatesPatent [191 Roth et al. Feb. 27, 1973 [54] FLOW SWITCH ASSEMBLY [57] ABSTRACT Inventors! Alton A. Roth; Don Dllobl, both In a preferred form, this disclosure relates to a flow of g J g", switch assembly comprising a housing means having a kenmllth, all of Michpair of hollow metal housing members which are insu- [73] Assign: General Motors Corporation, lated from each other and which define a flow passage Detroit Mich therethrough. The assembly also includes a vane member which is pivotally supported for movement Filed: l 1971 between first and second positions and a spring [21] AppLN 181883 member which biases the vane member to its first position and normally has its opposite ends engaged with the metal members to provide a conductive path [52] US. Cl ..200/81.9 R, 200/166 BA th rebetweem The housing means has a recess which [51] Int. CI. ..H0lh 35/40 e t nds adiall from the flow passage at a location Field 166 166 BB; between the first and second positions of the vane 73/223 member. The vane member is moved from its first toward its second position in response to a fluid flow l l References Cited in excess of a first predetermined magnitude flowing UNITED STATES PATENTS therethrough to break the conductive path and, when the flow decreases to below a second predetermined 1,513,361 10/1924 Airey ..200/81.9 R magnitude less than the first, the vane member moves 1,693,309 1928 e e w 0 R toward its first position. The recess provides an instan- 3,119,979 1/1954 Marti" ZOO/81'9 R X taneous increase in the flow passage area available for 2,773,963 12/1956 Mathews ..200/l53 Primary Examiner-Robert K. Schaefer Assistant Examiner-Robert A. Vanderhye Attorney-W. E. Finken et al.

fluid flow when the vane member moves toward its first position and is aligned therewith to enable thev spring member to rapidly shift the vane member to is first position.

3 Claims, 4 Drawing Figures PATENTEDFEBZYW 8.718788 ATT NE FLOW SWITCH ASSEMBLY The present invention relates to a flow switch assembly, and more particularly to a flow switch assembly which responds to a flow in excess of a first predetermined magnitude to open a circuit and which responds to a flow less than a second predetermined magnitude to close the circuit.

Flow switch assemblies have heretofore been provided with vane members which are adapted to move from a first position to a second position in response to a fluid flow in excess of a predetermined magnitude to open or break a circuit. For example, see U.S. Pat. No. 859,147. Flow switch assemblies have also been provided wherein the vane member is spring biased toward a first position to maintain an electric circuit closed. For example, see U.S. Pat. No. 3,119,979. Further, flow switch assemblies have been provided. with the above-described features and with the housing of the assembly constituting a conductive element or elements in the electric circuit. For example, see U.S. Pat. No. 1,693,309.

The present invention provides a new and improved flow switch assembly of the above noted type and which is constructed and arranged such that the switch is rapidly opened in response to a fluid flow in excess of a first predetermined magnitude flowing therethrough, rapidly closed when a fluid flow less than a second lesser predetermined magnitude flows therethrough, but which is not sensitive or opened and closed due to fluctuations in the fluid flow rate between the first and second magnitudes.

An object of the present invention is to provide a flow switch assembly having a housing means with a flow passage which is adapted to receive a fluid flow and which includes a pair of metal elements which are electrically insulated from each other, a vane member which is pivotally supported by the housing means for movement between first and second positions, a spring member which biases the vane member toward its first position and which has one end in constant engagement with one of the elements of the housing means and its other end or the vane member in engagement with the other of the elements when the vane member is in its first position to provide a conductive path between the elements, and a recess in the housing means extending radially from the flow passage at a location intermediate the first and second positions of the vane member and in which the vane member is rapidly movable from its first position toward its second position when a fluid flow in excess of a first predetermined magnitude passes through the flow passage and is movable from its second position toward its first position when the fluid flow falls below a second lesser predetermined magnitude, the recess serving to provide an increase in the flow passage area available for fluid flow when the vane member moves therepast toward its first position whereby the fluid pressure on the vane is relieved so that the spring member rapidly shifts the vane member to its first position to again provide a conductive path between the elements.

These and other objects of the invention are accomplished, in the preferred embodiment, by providing a flow switch assembly having a housing means with a flow passage therethrough adapted to receive a fluid flow. The housing means includes an annular fitting member with a counterbored portion having an annular collar member of insulating material which is received within the counterbored portion. The housing means also includes a tubular member which has one end portion which is flanged radially outwardly with an annular insulating seal received thereon and which has one end portion received within the counterbored portion of the fitting member. The tubular member has a terminal means which is fixedly attached thereto for connecting the tubular member to a power source.

The assembly also includes a vane member which is pivotally supported at one end upon a pivot pin carried by the collar member for movement between a first position and a second position. A torsion spring member with a coil portion supported upon the pivot pin has one bent end portion extending through a hole in the vane member and in engagement with the fitting member when the vane member is in its first position and has its other bent end portion in constant engagement with the tubular member to thereby provide a conductive path between the fitting and tubular members. The collar member also has a counterbored portion which with the counterbored portion of the fitting member defines a recess which extends radially of the flow passage at a location which is intermediate the first and second positions of the vane member. The vane member increasingly restricts the flow passage as it moves from its first position toward an intermediate position adjacent the recess and increasingly restricts the flow passage when it is moved from its second position toward its intermediate position. The vane member is movable from its first to its second position upon a fluid flow in excess of a first predetermined magnitude and remains between its intermediate and second positions unless the fluid flow decreases belowa second predetermined magnitude less than the first predetermined magnitude whereupon the vane member is moved past its intermediate position toward its first position. The recess serves to provide an increase in the flow passage area which is available for fluid flow to decrease the fluid pressure on the vane member whereby the spring member can rapidly shift the vane member to its first position to complete the conductive path.

These and other objects of the present invention will become more fully apparent from the following description and drawing wherein:

FIG. 1 is an end elevational view of a preferred embodiment of the flow switch assembly of the present invention;

FIG. 2 is a cross-sectional view taken approximately along the line 2-2 of FIG. 1;

FIG. 3 is a perspective view of a part of the subject flow switch assembly of the present invention; and

FIG. 4 is a cross-sectional view taken approximately along line 4-4 of FIG. 2.

As representing the preferred embodiment of the present invention, the drawings show a switch assembly 10. Although the switch assembly 10 could be used for different purposes, it is particularly susceptible for use in a system wherein an electrically operated device is to be deenergized when a fluid flow occurs in excess of a first predetermined magnitude and wherein it is desira ble that the electrically operated device be energized again when the fluid flow decreases to below a second predetermined magnitude which is less than the first predetermined magnitude.

The switch assembly broadly comprises a housing means 12 which has a flow passage 14 therethro'ugh, a

vane member 16 which is pivotally supported by the housing means 12 within the flow passage 14, and a spring member 18 which normally biases the vane member 16 to a first or closed-circuit position to provide a conductive path between different portions of the housing means 12.

Referring to FIGS. 1 and 2, the housing means 12 includes an annular fitting or housing member 20, a tubular or housing member 22, and an annular collar member 24. The housing member 20 is of any material having suitable electrically conductive properties and has a central cylindrical bore 26 therethrough. The lefthand end portion 27, as shown in FIG. 2, of the fitting member 20 is externally threaded and adapted to be threadably connected to a component (not shown) in a fluid flow system. The fitting member 20 carries a conventional rubber seal 28 in a concentric manner about its midpoint and immediately adjacent the threaded end portion 27. In this respect, the seal 28 will be positioned between one end of the component (not shown) and a flanged portion or shoulder 20a on the fitting member 20 when the latter is threadably connected to the component to provide a sealed joint therebetween. Further, the central bore 26 has three counterbored portions 31-33 in the right-hand end portion 29 of the fitting member 20.

The annular collar member 24 is of any suitable electrically insulating material, such as plastic, and has a centrally located aperture 34 therethrough. Referring to FIG. 4, the end view of the aperture 34 shows the lower portion 34a of the aperture 34 to be generally rectangular in shape with squared lower corners and the upper portion 34b to be formed in a rounded manner. Further, the collar member 24 includes a semi-circular radially outwardly extending recess 36 which extends axially from the left-hand end portion of the collar member 24, as shown in FIG. 2, and in a circumferential manner about theupper roundedportion 34b of the aperture 34, as shown in FIG. 4. The collar member 24 has its outer periphery shaped in a circular manner which is complementary to the counterbored portion 3l-of the housing member 20 and is received therein such that the aperture 34 is aligned with the bore 26. In this respect, the recess 36 is located immediately adjacent the bottom wall 37 of the counterbored portion 31 of the housing member 20.

The tubular member 22 has a cylindrical opening 44 therethrough of substantially the same radius as the bore 26 of the fitting member 20 and the upper portion 34b of the aperture 34 of the collar member 24. The left-hand end portion 22a, as shown in FIG. 2, of the tubular member 22 has a radially outwardly extending flange 46 which has an annular seal 48 of electrically insulating material received thereon. The right-hand end portion 22b of the tubular member 22, as shown in FIG. 2, is suitably adapted to be connected to a second annular component (not shown), such as a hose, in a fluid system and attached thereto by some suitable means, such as a clamp ring. The tubular member 22 also includes a suitable terminal 50 which is fixedly mounted to the outer periphery of the tubular member 22 and which is carried by insulating socket 52. In this manner, the tubular member 24 which is of electrically conductive material can be connected to a power source or within an electrical circuit. The left-hand end portion of the tubular member 22, as shown in FIG. 2, is positioned within the counterbored portion 32 of the fitting member 20 immediately adjacent the collar member 24 such that the opening 44 is in a substantially coaxial relationship with the bore 26 of the fitting member 20. An annular retainer ring 54 is positioned within the counterbored portion 33 of the fitting member in juxtaposition with the seal 48 and flange 46 of the tubular member, and the right-hand end portion 29 of the fitting member 20 is bent over or crimped radially inwardly and around the ring 54 to fixedly attach the tubular member 22 thereto.

It should be noted that the bore 26 of the fitting member, the aperture 34 of the collar member 24, and the opening 44 of the tubular member 22 define the flow passage 14 and that the switch assembly 10 is thereby adapted to receive a fluid flow therethrough. It should also be noted that the recess 36 of the collar member 24 provides an increased area for fluid flow within the flow passage 14.

Now referring to FIGS. 2 and 3, the vane member 16 is generally complementary in shape to the aperture 34 of the collar member 24 and slightly undersize with respect thereto. The vane member 16 has a flat body portion 55 with a pair of ear portions 56 at its lower end which have a pair of aligned holes 58 therethrough. The vane member 16 is pivotally supported by the collar member 24 upon a pivot pin 60. The pivot pin 60 extends through the holes 58 in the ear portions 56 and v has its opposite ends received within holes (not shown) in the lower portion of the collar member 24.

The spring member is a torsion spring made of electrically conductive material and which has its midportion formed into a plurality of coils 62. A pair of bent end portions 64 and 65 extend perpendicularly in different directions from opposite ends of the coiled portion 62. The spring member 18 has its coiled portion 62 encircling the pivot pin 60 between the ear portions 56 of the vane member 16. The spring member 18 is normally self-biased into engagement with both the tubular member 22 and the fitting member 20. The bent end portion 65 of the spring member 18 projects from one end of the coiled portion 62 and is in constant engagement with the inner periphery 67 of the tubular member 22 which defines the opening 44. The other bent end portion 64 projects from the opposite end of the coiled portion 62 and extends through a hole 69 in the center of the body portion 55 of the vane member 16 to engage the inner periphery 71 of the housing member 20 which defines the bore 26.

The spring member 18 biases the vane member 16 to a normal or first position, as shown by the solid lines in FIG. 2, in which the body portion 55 of the vane member 16 projects at approximately a 45 angle from a vertical plane extending perpendicular to the axis of the aperture 34. The vane member 16 is adapted to be moved from its first position to a second position, as shown by the phantom lines in FIG. 2, against the bias of the spring member 18 when a fluid flow in excess of a first predetermined magnitude is flowing through the flow passage 14. Further, the bias of the spring member 18 is effective to move the vane member 16 from its second position to an intermediate position, as shown by the dotted lines in FIG. 2, against the pressure of the fluid flow when the fluid flow decreases to a second predetermined magnitude.

In operation, a circuit can be traced from a power source (not shown), a connector (not shown), the terminal 50, the tubular member 22, the bent end portion 65 of the spring member 18, the coil 62 of the spring member 13, the other bent end portion 64 of the spring member 18, the housing member 20, to ground G when the vane member 16 is in its first position. The vane member 16 remains in its first position and the above described circuit remains completed through the spring member 18 as a result of the bias of the spring member 18 until a fluid flow is received within the flow passage 14 in excess of a first predetermined magnitude. It should be readily apparent that, when a fluid flow is reached which has sufficient magnitude to cause the vane member to move from its first position toward a vertical position, the vane member 16 will increasingly restrict the flow passage 14 as it moves toward the vertical position. The increasing restriction of the flow passage 14 by the vane member 16 results in increasing fluid pressure upon the vane member 16 which serves to rapidly pivot the vane member to its second position against the bias of the spring member 18. In this regard, the movement of the vane member 16 causes the bent end portion 64 of the spring member 18 to be disengaged from the inner periphery 71 of the fitting member 20 and, consequently, the above-described circuit is broken.

It should also be readily apparent that, when the fluid flow decreases below the first predetermined magnitude, the bias of the spring member 18 causes the vane member 16 to pivot from its second position toward a vertical, intermediate position and the vane member will again increasingly restrict the flow passage 14. Hence the increasing restriction of the flow passage 14 by the vane member 16 again results in increasing fluid pressures upon the vane member 16 which serve to maintain the vane member between its second position and its intermediate position until the fluid flow decreases to below a second predetermined magnitude. Thus, the bent end portion 64 of the spring member 18 is maintained out of engagement with the fitting member 20 and the circuit is maintained open as long as the fluid flow is equal to or greater than a second predetermined magnitude. When the fluidflow decreases to below the second predetermined magnitude, the bias of the spring member 18 causes the vane member 16 to be pivoted beyond its intermediate position into the portion of the fluid passage having increased area for fluid flow as provided by the recess 36 of the collar member 24. The recess 36 provides an instantaneous increase in the flow passage area available for fluid flow and the restriction of the flow passage 14 by the vane member 16 is instantaneously decreased. The instantaneous decrease in the restriction of the flow passage 14 results in sudden decrease in the fluid pressure on the vane member 16, and the bias of the spring member 18 serves to rapidly shift the vane member 16 to its first position. The bent end portion 64 of the spring member 18 thereby again engages the inner periphery 71 of the fitting member 20 and the above-described circuit is again closed to effect energization of the electrical means (not shown).

One advantage of the flow switch assembly of the present invention is the hysteresis effect it presents once the switch is opened. That is, the switch assembly 10 will not open until a fluid flow of a first predetermined magnitude occurs, but thereafter the flow switch assembly tolerates all variations and fluctuations in the fluid flow rate between the first and the lesser second predetermined magnitude without closing. Further, once the flow rate decreases to below the second predetermined magnitude, the closing of the switch assembly 10 is rapid.

The foregoing disclosure relates to only one embodiment of the invention which may be modified within the scope of the appended claims.

What is claimed is:

l. A flow switch assembly, comprising: a housing means having a flow passage therethrough adapted to receive a fluid flow, said housing means including a pair of metal elements electrically insulated from each other; a vane member pivotally supported by said hous ing means for movement between a first position and a second position; a spring member for biasing said vane member toward its first position, said spring member having one end in constant engagement with one of said elements of said housing means and one of said vane and spring members being in engagement with the other of said elements when said vane member is in its first position to provide a conductive path between said elements; said housing means having a recess extending radially outward from said flow passage at a location intermediate said first and second positions of said vane member, said vane member increasingly restricting the flow passage as it moves from its first position towards an intermediate position adjacent said recess and in creasingly restricting the flow passage when moved from its second position toward its intermediate posi-.

through said flow passage, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage available for fluidflow when said vane member moves past its intermediate position toward its first position to decrease the fluid pressure upon said vane member whereby said spring member rapidly shifts said vane member to its first position to again provide a conductive path between said elements.

2. A flow switch assemblyfor controlling energization of electrical means, comprising: a housing means having a flow passage therethrough adapted to receive a fluid flow, said housing means including first and second annular metal elements electrically insulated from each other, said first annular element having a counterbored portion; a vane member pivotally supported by said housing means for movement between a first position and a second position; a spring member for biasing said vane member toward its first position, said spring member having one end in constant engagement with said second annular element of said housing means and having its other end in engagement with said first annular element when said vane member is in its first position to provide a conductive path between said first and second annular elements and effect energization of theelectrical means; an annular collar member received within said counterbored portion of said first element of said housing means and also having a counterbored portion, said counterbored portions defining a recess extending radially of said flow passage at a location intermediate the first and second positions of said vane member; said vane member increasingly restricting said flow passage as it moves from its first position toward an intermediate position immediately past said recess and increasingly restricting the flow passage when moved from its second position toward its intermediate position, said vane member being movable from its first position toward its second position upon a fluid flow in excess of a first predetermined magnitude flowing through said housing means, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage area available for fluid flow when said vane member moves past its intermediate position toward its first position to decrease the fluid pressure against the vane member whereby said spring member rapidly shifts said vane member to itsfirst position to effect energization of the electrical means.

3. A flow switch assembly for controlling energization of an electrical means, comprising: a housing means having a flow passage adapted to receive a fluid flow, said housing means including an annular fitting member with a counterbored portion having an annular collar member of insulating material received within said counterbored portion, said housing means also including a tubular member having one end portion flanged radially outwardly with an annular insulating seal received thereon and having said one end portion received within said counterbored portion, said tubular member having terminal means fixedly attached thereto for connecting said tubular member to a power source; a vane member pivotally supported at one end upon a pin projection of said collar member for movement between a first position and a second position; a torsion spring member having a coil portion supported within said flow passage upon said pin projection of said collar member, said spring member having one bent end portion extending through a hole in said vane member and biasing said vane member toward its first position, said spring member having said one bent end portion in engagement with said fitting member when said vane member is in its first position and having its other bent end portion in constant engagement with said tubular member to provide a conductive path between said fitting and tubular members to effect energization of the electrical means; said collar member having a counterbored portion, and said counterbored portions of said fitting member and said collar member defining a recess extending radially of said flow passage at a location intermediate the first and second positions of said vane member; said vane member increasingly restricting the flow passage as it moves from its first position toward an intermediate position immediately past said recess and increasingly restricting said flow passage when moved from its second position toward its intermediate position, said vane member being movable from its first position toward its second position upon a fluid flow in excess of a first predetermined magnitude within said flow passage, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage area available for fluid flow when said vane member moves past its intermediate position toward its first position to decrease the fluid 

1. A flow switch assembly, comprising: a housing means having a flow passage therethrough adapted to receive a fluid flow, said housing means including a pair of metal elements electrically insulated from each other; a vane member pivotally supported by said housing means for movement between a first position and a second position; a spring member for biasing said vane member toward its first position, said spring membEr having one end in constant engagement with one of said elements of said housing means and one of said vane and spring members being in engagement with the other of said elements when said vane member is in its first position to provide a conductive path between said elements; said housing means having a recess extending radially outward from said flow passage at a location intermediate said first and second positions of said vane member, said vane member increasingly restricting the flow passage as it moves from its first position towards an intermediate position adjacent said recess and increasingly restricting the flow passage when moved from its second position toward its intermediate position, said vane member being movable from its first position toward its second position when a fluid flow in excess of a first predetermined magnitude passes through said flow passage, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage available for fluid flow when said vane member moves past its intermediate position toward its first position to decrease the fluid pressure upon said vane member whereby said spring member rapidly shifts said vane member to its first position to again provide a conductive path between said elements.
 2. A flow switch assembly for controlling energization of electrical means, comprising: a housing means having a flow passage therethrough adapted to receive a fluid flow, said housing means including first and second annular metal elements electrically insulated from each other, said first annular element having a counterbored portion; a vane member pivotally supported by said housing means for movement between a first position and a second position; a spring member for biasing said vane member toward its first position, said spring member having one end in constant engagement with said second annular element of said housing means and having its other end in engagement with said first annular element when said vane member is in its first position to provide a conductive path between said first and second annular elements and effect energization of the electrical means; an annular collar member received within said counterbored portion of said first element of said housing means and also having a counterbored portion, said counterbored portions defining a recess extending radially of said flow passage at a location intermediate the first and second positions of said vane member; said vane member increasingly restricting said flow passage as it moves from its first position toward an intermediate position immediately past said recess and increasingly restricting the flow passage when moved from its second position toward its intermediate position, said vane member being movable from its first position toward its second position upon a fluid flow in excess of a first predetermined magnitude flowing through said housing means, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage area available for fluid flow when said vane member moves past its intermediate position toward its first position to decrease the fluid pressure against the vane member whereby said spring member rapidly shifts said vane member to its first position to effect energization of the electrical means.
 3. A flow switch assembly for controlling energization of an electrical means, comprising: a housing means having a flow passage adapted to receive a fluid flow, said housing means including an annular fitting member with a counterbored portIon having an annular collar member of insulating material received within said counterbored portion, said housing means also including a tubular member having one end portion flanged radially outwardly with an annular insulating seal received thereon and having said one end portion received within said counterbored portion, said tubular member having terminal means fixedly attached thereto for connecting said tubular member to a power source; a vane member pivotally supported at one end upon a pin projection of said collar member for movement between a first position and a second position; a torsion spring member having a coil portion supported within said flow passage upon said pin projection of said collar member, said spring member having one bent end portion extending through a hole in said vane member and biasing said vane member toward its first position, said spring member having said one bent end portion in engagement with said fitting member when said vane member is in its first position and having its other bent end portion in constant engagement with said tubular member to provide a conductive path between said fitting and tubular members to effect energization of the electrical means; said collar member having a counterbored portion, and said counterbored portions of said fitting member and said collar member defining a recess extending radially of said flow passage at a location intermediate the first and second positions of said vane member; said vane member increasingly restricting the flow passage as it moves from its first position toward an intermediate position immediately past said recess and increasingly restricting said flow passage when moved from its second position toward its intermediate position, said vane member being movable from its first position toward its second position upon a fluid flow in excess of a first predetermined magnitude within said flow passage, said vane member remaining between its intermediate and second positions unless said fluid flow decreases below a second predetermined magnitude less than said first predetermined magnitude whereupon said vane member moves past its intermediate position toward its first position, said recess serving to increase the flow passage area available for fluid flow when said vane member moves past its intermediate position toward its first position to decrease the fluid pressure upon said vane member whereby said spring member can rapidly shift said vane member to its first position to effect energization of the electrical means. 